We ranked them for you.
If you’ve been on the lookout for a new way to lose weight, you’ve probably noticed that low-carb,
high-protein diets—like Atkins, the ketogenic diet, and the Dukan diet—have become kind of a big deal.
Not only did all three make the cut on Google’s annual list of most searched diets, but two (Atkins and Dukan) are also on the 2016 US News & World Report’s roundup of best weight-loss diets.
Each of these diets follow the same basic premise: limiting carbs means the body turns to stored fat for fuel. But is one of these plans more likely to lead to pounds-shedding success?
We caught up with Edwina Clark, R.D., head of nutrition and wellness at Yummly, to find out how these three diets compare.
"The ketogenic diet is a high-fat, moderate protein, low-carb diet," says Clark. Up to 75 percent of your daily calories come from fat, 5 to 10 percent from carbs, and the rest from protein. By severely limiting carbs to 50 grams or less, this diet forces your bod to burn fat for energy, a process known as ketosis.
Unlike the Atkins and Dukan diets, the keto plan doesn’t work in phases. Instead, you sustain the low-carb, high-fat, high-protein eating ratios until you reach your goal weight. There is no maintenance plan once you reach your goal.
Unsurprisingly, limiting your carb intake this much means missing out on quite a few (delish) foods, including legumes, root vegetables, and most fruits. Starchy veggies, such as squash and sweet potatoes, are also off the table, along with refined carbs. Thanks to carb counting and food restrictions, meal prepping is paramount to following this plan.
The rapid weight loss you’ll experience at the start of this diet might be helpful in the motivation department, but you’re not dropping fat from the get-go, says Clark. "Carbs are stored with water, so when people ditch carbs they lose the water weight that goes with them," she says. Plus, carbs are also the body’s main energy source, so early restriction may leave you feeling fatigued, foggy, and grumpy.
Though you might feel restricted from bread and fruit, the plans emphasis on fat and protein, which moves slowly through the digestive tract, could make you feel more satisfied, says Clark. Plus, research suggests that the production of ketone bodies during ketosis can lower levels of ghrelin, a hunger hormone.
Unfortunately, that’s where the perks stop. "Sustainability of this eating approach is highly questionable," says Clark. "Prolonged periods of restriction may lead to nutrient deficiencies, especially since so many foods are cut from this diet." Since this plan has the lowest daily carb intake, compared to Atkins and Dukan, getting enough fiber each day would be very difficult, says Clark.
With so few foods on the menu, the diet could get very boring, very fast and might spark a Cookie Monster-like binge of all the foods you’ve been trying to avoid. In the end, as your body clings to every carb (kind of like your mom when she hasn’t seen you in a while), you may end up weighing more than when you started, says Clark.
Deprivation, bored taste buds, too much fat, nutritional deficiencies, and the potential boomerang effect put this diet in last place, Clark says.
The Atkins diet consists of four phases, says Clark. It doesn’t require calorie counting, but it does ask you to track your carbs, which can make the diet tricky to follow. In phase one (induction), you cut out almost all carbs, knocking your intake down to 20 grams of net carbs (carbs minus fiber = net carbs) per day, primarily from veggies. You’re also required to eat protein at every meal and three servings of added fat per day. This phase lasts an average of two weeks.
During phase two (balancing), the daily carb allowance goes up to 50 grams of net carbs and more sources of nutrition are added to the roster, says Clark. That means you can eat more veggies and berries, as well as nuts and seeds. You stay in this phase until you’re roughly 10 pounds away from your goal weight.
Phases three and four of Atkins are all about learning to maintain your goal weight once you’ve reached it. Phase three allows you to gradually increase the range of foods you can eat (such as fruits, starchy veggies, whole grains, and full-fat dairy). It also helps you figure out how many carbs you can eat while still losing weight by requiring you to add 10 grams of net carbs back into your diet until your weight stabilizes, says Clark. (If weight loss stops before you’ve reached your target, you know you need to scale back a bit.) This phase ends once you reach your goal weight and maintain it for four weeks. Phase four is full-on maintenance mode, where you continue the eating habits you solidified in phase three for life.
Because of the diuretic effect of restricting carbs, this diet will also jumpstart your weight loss efforts, says Clark. And with the spotlight on protein and fat, which take longer to digest than carbs, satiety shouldn’t be a problem.
There’s also a solid emphasis on eating real food and putting the kibosh on refined carbs, which cuts oodles of empty calories and added sugars. However, Atkins pedals its own line of food products, such as bars, protein drinks, and meals, that aren’t entirely healthful, says Clark. So be wary.
Again, the drastic drop in carbs could leave you feeling tired, cranky, and low on willpower. So the long-term sustainability of this diet is questionable, says Clark. "Some people may not be able to maintain the prolonged periods of restriction and end up back where they started," she says. Another bummer, you need to make an effort to ensure you’re getting enough fiber each day, she says.
Many dieters might find carb counting to be tedious, especially when they eat out. "The diet also doesn’t restrict fatty sources of protein (like bacon or certain cuts of steak), which is concerning," says Clark. Currently, it’s unclear how higher amounts of saturated fat in the Atkins diet affects long-term health, she says. Clark ranks this diet second because unlike the keto plan, the Atkins diet attempts to help dieters transition into a more sustainable way of eating and keeping weight off.
See the craziest diets people actually followed to lose weight.
The Dukan diet consists of four phases: two for losing weight, and two for maintaining, says Clark. The first phase (attack) involves eating only lean protein for one day to one week—depending on how much weight you have to lose—and you’re allowed to eat these foods in unlimited quantities, along with 1.5 tablespoons of oat bran per day. In phase two (cruise), non-starchy veggies are added to the list of permissible foods, and participants are encouraged to alternate between pure-protein and protein-plus-veggie days until they reach their target weight. Phase two also incorporates two tablespoons of oat bran per day.
Phase three (consolidation) is all about transitioning from a strict food list to a more liberal diet. Participants are still encouraged to have one full day per week of eating only protein-rich foods, says Clark. On the other days, they can have limited quantities of fruit, whole-grain bread, and cheese, in addition to the high-protein foods and non-starchy veggies. A maximum of two celebration meals are permitted per week, oat bran is capped at two tablespoons per day, and other grains are limited to two servings per week. This phase lasts five days per every pound lost in the cruise phase. So if you lost 20 pounds, you’d be following this plan for 100 days.
Phase four (stabilization) is an expanded, less structured version of the previous phase, says Clark. You can now eat foods from all food groups and three tablespoons of oat bran per day. Though, you still need to maintain one pure-protein day per week.
This diet is especially attractive if you don’t like counting calories or carbs. It’s a structured system that sets out exactly what you can eat, but the rules aren’t overly complicated and the periods of restriction are shorter compared to the other two diets, says Clark.
Even though the Dukan diet is super-restrictive during the first two phases (only allowing you lean protein from a list of 68 foods), the first phase sets you up for a quick drop on the scale, creating a strong incentive to stick with the program.
One concern: It’s recommended that you stay in the consolidation phase, where you only eat protein and non-starchy veggies, until you reach your target weight. But if you have a lot of weight to lose, this could cause a nutritional deficiency and encourage an unhealthy relationship with food, says Clark. "Achieving adequate fiber intake may also be a problem, especially if you don’t follow the oat bran recommendations during each phase," she adds. And that’s a problem since adequate fiber is uber-important for satiety, digestive health, and cholesterol control.
Phases three and four gradually add the rest of the food groups back into your diet, with the intent of helping you maintain your goal weight once you’ve reached it. Because of the restriction leading up to this point, people are more likely to gain weight once they introduce variety back into their diet, warns Clark. But this diet does try to alleviate that by gradually reintroducing carb-rich foods and celebration meals, which is more than the other plans do.
The Dukan diet is the easiest to follow and the periods of restriction are relatively short, says Clark. That keeps feelings of deprivation to a minimum. And unlike other low-carb, high-protein diets, this plan focuses on lean protein sources over those high in saturated fat, which is associated with inflammation and heart disease. The system also encourages participants to establish a support network and explore their motivations for following the Dukan plan, which is a great way to stay on the wagon. That’s why this plan came in first for Clark.
That being said, it’s worth noting that none of these diets are ideal because they all dramatically restrict carbs and other nutrients, says Clark. On top of that, they may create a negative relationship with food, causing you to consider some foods "good" and others "bad," which fuels food guilt and subsequent restriction.
These plans are very challenging to follow for sustainable weight loss, and can result yo-yo dieting behavior, says Clark. If you’re looking to lose weight by eating less carbs and upping your protein, start by reducing refined carbohydrates, like cereal, white pasta, and white bread, from your diet. Then, increase your protein intake by filling up on lean sources, like turkey, chicken, Greek yogurt, eggs, and fish. You can find out just how much protein you should be eating to lose weight here.
Krissy is a regular contributor to Prevention, and she also writes for Cosmopolitan, Weight Watchers, Women’s Health, FitnessMagazine.com, Self.com, and Shape.com.
The 9 Best Calorie-Burning Exercises, Ranked
6 Women Reveal What It Took To Lose 15 Pounds
80 Satisfying Lunches That Promote Weight Loss
These Diets Can Help You Lose Weight, For Good
9 Women Share How Long It Took To Lose 20+ Lbs.
‘I Quit Alcohol For Six Months And Lost 15 Pounds’
40 Foods That Have More Fiber Than A Fiber Bar
Nutritionist LOVE These Keto Meal Delivery Kits
How Do You Know You’re In Ketosis?
19 Ways To Lose Thigh Fat And Tone Your Legs
The Best Meal Delivery Services
Here’s How Much Veggies You Should Eat In A Day
A Part of Hearst Digital Media
Women’s Health may earn commission from the links on this page, but we only feature products we believe in.
©Hearst Magazine Media, Inc. All Rights Reserved.